Bobby Marks, 38

New Jersey Nets, Assistant general manager

Where is Bobby now?

The Nets' efforts to land Carmelo Anthony had fizzled, but Bobby Marks had no time to mope. With Mr. Marks maneuvering under the National Basketball Association's complex salary cap, the Nets promptly landed Utah Jazz star Deron Williams—unloading a package that included a draft pick Mr. Marks had stolen from the Golden State Warriors in an earlier deal.

As a Nets intern 16 seasons ago, Mr. Marks clipped articles about the team, never imagining he would one day be in those stories. The former Marist College football player wanted to be a police officer.

"I caught a lot of breaks," Mr. Marks said. "I learned the business from the startup level. That's how I got my foot in the door."

Nets General Manager Willis Reed kept him on after his internship. He learned under John Calipari and Rod Thorn, rising to vice president for basketball operations at 34 and, when Billy King became general manager, assistant GM at 38.

Mr. Marks became indispensable by mastering the salary cap and collective bargaining agreements. He plays leading roles managing the Nets' $60 million payroll, scouting, trades, long-term planning and its Developmental League affiliate. And he's media-savvy: As reporters waited out a lengthy negotiating session during last fall's lockout, he sent pizza.

His fairy-tale climb has one unwritten chapter. "I'd love to run a team," he said. He was considered for the Portland Trail Blazers' GM job in 2010, and ESPN's Chad Ford called him one of "five guys who should be running their own teams," according to the blog Nets Daily.

"He has the ability," Mr. King said. "I've taken it personally to help prepare him for that. I try to give him as much responsibility as possible."